Okay so I think the design of ACNL 3Ds xl is cuter than HHM new 3Ds xl design but I kind of want a system upgrade. Idk if new system is worth it. Only way I could afford is to sell my old one. What do you guys think? Which is better design in your opinion? (Google img system if you need reference)

Moving to the Video Gaming & Consoles board.

You can't sell your old system if you want to keep all of your save data, Nintendo Network ID, and Nintendo eShop account and purchases, as the System Transfer process needs to be performed, which requires having the original system, the replacement system, and an open internet connection.

Now, not to sound uneducated, but what exactly does "HHM" stand for? I don't believe I've heard of this particular design.

Happy Home Designer...I keep thinking maker instead of designer which is why it was M and not D

Ah, I see. Well, not to be nit-picking here, but the Happy Home Designer system is actually a New Nintendo 3DS, not a New Nintendo 3DS XL. The New Nintendo 3DS system overall offers more options for personalization, as not only does it come with two cover plates, giving you four options for designs, but you can also purchase additional cover plates for more options, including Kirby, Pikachu, K.K. Slider, The Legend of Zelda, and Super Smash Bros. among others. Being a New system, it can also play games that the Nintendo 3DS, Nintendo 3DS XL, and Nintendo 2DS systems cannot, including Xenoblade Chronicles 3D.

Actually theres a HHD New 3DS XL in Japan.